THE PRESIDENT'S WAR ON CRIME

Published: February 23, 1986

President Reagan informs us that some unions ''when discovered doing business with the mob'' have ''launched a vain attempt to protect their reputation and try to obstruct law-enforcement investigations.''

The close, if increasingly controversial, ties between current Teamster president Jackie Presser and Mr. Reagan's own Administration and party strongly suggest that this has not always been a ''vain attempt.''

If Mr. Reagan is really concerned about rooting out corruption in the labor movement, he might begin by taking his own advice about refusing to patronize or do business with the Jackie Presser leadership of the International Brotherhood of Teamsters and, instead, support the trade unionists in rank-and-file reform groups, like Teamsters for a Democratic Union, who are struggling to rid their union of organized-crime influence. STEVE EARLY Arlington, Mass.